Problem: Assume this first statement is true: If two angles are vertical angles, then the two angles are congruent. Logically, can you deduce that this second statement must be true from the first one? If two angles are congruent angles, then the two angles are vertical angles.
Solution: Is the second statement the converse, inverse, or contrapositive of the original statement? The second statement is the converse of the original statement. The converse is not logically equivalent to the original statement, so no, the second statement cannot be deduced from the first statement.